AtApple has released release candidates for tvOS 14.3 and watchOS 7.2 to developers. These are near-final builds and will likely be released to all users in a few days.
tvOS 14.3 release candidate features under-the-hood performance improvements, and possibly support for Fitness+, while watchOS 7.2 will ship with a few new features including Cardio Fitness measurements and Fitness+.
Despite reaching its release candidate status, Apple still has not shared any release notes for tvOS 14.3. However, given that the launch date for Apple Fitness+ is less than a week away, tvOS 14.3 will include support for the new service.
Fitness+ will allow users to watch trainer guided videos for various workouts on Apple TV, while also showing their progress via Apple Watch on the big screen, so they can see their metrics. Although the service is primarily based on Apple Watch, it will be use metrics from the Watch to display them on Apple TV, iPad or iPhone so users can see them on the screen.
Apple is also releasing some UI updates for Apple TV+ with iOS 14.3, so it is possible that Apple TV will also get the same enhancements.
Apple had launched tvOS 14 a few months ago with gaming updates, YouTube 4K support, picture-in-picture video playback, HomeKit controls, and more.
The newest watchOS 7.2 update includes a new Cardio Fitness feature that measures overall health by calculating the amount of oxygen (VO2Max) that your body can consume during exercise. Apple Watch sensors work with iPhone and track data over a period of time to give the measurement in Health and Activity apps. Cardio Fitness will be a good way for Watch users to understand how their health has improved or deteriorated over a period of time, and allow them to take appropriate actions. To use the new feature, you will also need to be on iOS 14.3 release candidate.
If you are already on an existing beta build, simply go to Watch > Settings > General > Software Update to download the release candidate. Make sure that your Watch has at least 50% battery and is placed on its charger during the update process.
Apple had released watchOS 7 a few months ago with new watch faces, watch face sharing, sleep tracking, handwash detection, family setup, new workouts, Apple Maps updates and more.